WO1986004622A1

WO1986004622A1 - Paper manufacturing method

Info

Publication number: WO1986004622A1
Application number: PCT/JP1986/000045
Authority: WO
Inventors: Naoya Tashiro; Hiroshi Uehara
Original assignee: Mitsubishi Paper Mills, Ltd.
Priority date: 1985-02-08
Filing date: 1986-02-05
Publication date: 1986-08-14
Also published as: DE3687729D1; EP0217959A4; US4935097A; EP0217959A1; EP0217959B1; DE3687729T2

Abstract

A paper manufacturing method capable of obtaining paper which meets the requirements for the smoothness and stiffness (rigidity) of the surface thereof. This method is characterized in that the paper having a bonedry water content of 1.8-7% is treated by a thermal calender under the conditions including a temperature of 150?o-300?oC and a linear pressure of not less than 40 kg/cm, to obtain paper suitably used as a support for photographs.

Description

Manufacturing method of specification paper Technical field

The present invention relates to a method for producing paper, which satisfies both surface smoothness and stiffness (resilience), and is preferably used as a photographic support, although not limited thereto. It relates to the manufacturing method of the paper used.

Background technology

Methods for smoothing the surface of paper include selection of pulp material, calendering, increasing pressure, and increasing paper density. In addition, in order to strengthen the waist, there are methods such as selecting the material of the zorup and increasing the umbrella height. However, processing to increase the smoothness of the surface quality of paper and processing to increase the firmness (stiffness) are contradictory, and it has been difficult in the past to satisfy both. rice field .

Invention disclosure

The above-mentioned problems of the prior art are solved by calendering paper with an absolute dry moisture content of 1.8-7% at a temperature of 150-300°C and a linear pressure of 40°C or higher. The problem was solved by a paper manufacturing method characterized by:

Therefore, according to the present invention, paper having an absolute dry moisture content of 1.8 to 7% is _calendered under conditions of a temperature of Ί5Q to 3Q0 and a linear pressure of 40 or higher. It is in the manufacturing method of the characteristic paper. .

MODE FOR CARRYING OUT THE INVENTION

The paper used in the present invention may be obtained using any kind of pulp, and may contain internal chemicals such as sizing agents and fluorescent agents. However, it is preferably obtained, for example, by the following method.

That is, a predetermined percentage of the

Mixed pulps made of NBSP, for example, alkylketene dimers, polyacrylamides, polyamides, piclorhydrin, starch, fluorescent agents, etc. Additives are added to form a sheet of paper with a predetermined basis weight, and after drying and before ripening calendering, an inorganic material such as denatured polyvinyl alcohol, food tray, etc., is used as a surface sizing agent. Add electrolyte and fluorescent agent. As will be described later, the surface sizing treatment may be performed after the thermal rendering treatment.

The reason why the absolutely dry water content of the paper used in the method of the present invention is limited to 1.8 to 7% is that when the water content is less than 1.8%, the effect of the ripening renderer treatment is reduced. If it is less than 7%, the surface quality will be poor. This is because such things do not occur.

Also, in the present invention, the temperature of the thermal rendering process is

The reason for limiting the temperature to 150 to 300°C is that if the temperature is less than 150°C, a smooth surface with large irregularities on the surface of the paper can be obtained, unlike conventional calendering. It is smooth when it exceeds 300. This is because a smooth surface can be obtained without the above-mentioned problems at a value between 150 and 300, whereas not only the deterioration of the hardness but also the problem of paper staining occurs. be . Heating is performed by means of electric heat, electromagnetic induction, or the like.

In addition, the reason why the linear pressure for ripe calendering is limited to 40 ½ / or more in the present invention is that smooth surface quality can be obtained with a cylinder not exceeding 40 ½ /. This is because there is no

In the present invention, the ripe calendering treatment is performed either before or after the surface sizing treatment (for example, using a modified polyvinyl alcohol aqueous solution). You can do it later.

As is clear from the examples described later, (i) when the absolute dry moisture content of the paper to be thermally calendered is 2. & to 5%, (ii) the ripe calender (iii) when the air permeability of the paper to be calendered is 3 QQ'sec or less, (iv) Particularly favorable results are obtained when the linear pressure of ripening calendering is 60½ or more.

Also according to the present invention, after hot calendering, moisture may be added to adjust the final moisture content. Depending on the purpose and application, water content may be added as a surface strength agent (for example, polyvinyl alcohol, starch, casein, gelatin, SBR, NBR, polyacrylamide). It may be imparted using an aqueous solution containing one or more kinds of dyes, fluorescent agents, antistatic agents, anticaprilating agents, etc. By imparting moisture, the final moisture content is, for example, 6 % or higher. The adjustment of the final moisture content to, for example, 6% or more by adding moisture as described above and the addition of various additives to the moisture content allow the paper obtained in the present invention to be used as a photographic support, which will be described later. It is preferable to do it when the time comes.

5. The paper obtained by the present invention is particularly suitable for photographic supports (paper supports and resin-coated supports) that must be enhanced in stiffness and surface smoothness. It is preferred to use For example, the fabric obtained by this method can be used directly as a support for photographic paper such as black-and-white copying paper and DTR method copying paper.

10 However, it is also possible to apply non-printing pigments such as paraitha to the paper as in the case of black-and-white photographic paper. In addition, like general color photographic paper, it can be coated with a polyolefin resin such as polyethylene by, for example, an extrusion coating method to obtain a photographic resin coating. It can also be used as a support. Paper obtained by this method

Copy paper and photographic paper using 15 have satisfactory stiffness and good smoothness.

Concerning the curvature, when the paper obtained in the present invention is used as a photographic paper support, it has a taper curvature of Ί1-απ or more when the thickness is Ί65. When the thickness is 1 7 5 xz 1 3 3 — or more

It has a taper angle of 20 degrees. The photographic resin-coated paper support provided with a resin coating layer on both sides of the paper obtained in the present invention has a base paper thickness of 165 xz and a total thickness of 220 x 16.5. ? - Have a taper angle of 191 or more when the base paper thickness is 175 and the total thickness is 230 c

25 The paper obtained by the present invention has less unevenness on the surface and is smoother. Since it is excellent, it is used as a photographic support, and when emulsion is applied to it, the so-called Ε shift (photographic emulsion applied to the support) does not occur. The misalignment of some layers of the multi-layered grooves that occurs when the grooves are formed is less likely to occur. In addition, swelling of the emulsion layer after wet photographic processing is small, and scratches and peeling of the emulsion are less likely to occur.

Example

The present invention will be further described by the following examples, but the present invention is not limited to these examples.

Examples Ί-5 and Comparative Examples 1-2

NBSP20 heavy parts, LBSP50 parts by weight and

Pulp blended with 30 parts by weight of LBKP was beaten to a freeness of 300^, and an alcohol containing alkylketene dimer as a main component was added to the pulp slurry as a sizing agent. Pel (manufactured by Dick Hercules), Stargum (manufactured by Seiko Kagaku) whose main component is polyacrylamide as a strength agent, and polyamic Epinox (manufactured by Deitzk Hercules), the main component of which is epichlorohydrin, is expressed as the content in the paper sheet. It was added at 0.5% by weight, 2% ^0/0 by _weight and 0.5% by weight of the pulp to form paper webs with a basis weight of 1803 and dried. Furthermore, the surface was sized using a modified poval aqueous solution as a surface sizing agent, dried, and dried to an absolute dry moisture content of 5%, air permeability of 60 sec, and internal bonding strength of 2.3 Ks - cm-sized paper, linear pressure 150 Ζ, temperature 120, Ί45, 150, 160, 200, 270, It was heat calendered at 300 °C. Table 1 shows the test results of the obtained paper.

( 1 ) Mature calendar humidity surface

Comparative Example 120Ό4.5

2 1 4 5 ° C 4 . 2 5 Example 1 1 5 0 4 , 0 n 2 1 6 0 4 . 0

11 3 2 0 0 3 . 7 5

// 4 2 7 0 3 . 5

;/5-300.4.0 Note (1):

Surface texture is evaluated by grading the degree of unevenness on the surface of the paper with the naked eye. The lower the numerical value at that time, the smaller the irregularities on the surface of the paper, and the smoother it looks. If the grade exceeds 4, the irregularities on the surface of the paper are large, and it is difficult to call it a smooth surface.

Table 1 shows that when the ripening calendering temperature is less than Ί50, the surface of the paper becomes uneven and a smooth surface cannot be obtained. Also, when the thermal calender temperature exceeds 300°C, there is a tendency for the surface texture to deteriorate.

On the other hand, when the ripe calendering temperature is 150 to 300°C, the paper surface grade is suppressed to 4 F or less, and the surface of the paper is less uneven and smoother. You can get good quality paper. Examples 6-"!0 and Comparative Examples 3-4

Pulp blended with NBSP 20-weight part a, LBSP 50-weight part S, and BKP 30-weight part S was beaten to a water resistance of 3 002, and the resulting pulp was added to a slurry with a sizing agent. Acopel (manufactured by Dick-Hercules), which is mainly composed of alkene dimer, is used as the main component, and polyacrylamide is mainly used as the strength agent. Star gum (manufactured by Seiko Kagaku Co., Ltd.) and Epinox (Deitku 8 (manufactured by Cures Co.) was added to the pulp at 0.5 weight %, 2 m weight %, and 0.5 weight %, respectively. OT paper with absolute dry moisture content of 2.5%, air permeability of 60 sec, internal bonding strength of 2.3 — _OT paper obtained by drying to form a paper sheet with a basis weight of Ί 80. , linear pressure Ί 50 K/cm, temperature Ί 2 〇, 145, 150, 160, 200, 27 〇 , calendered at 300 °C, surface sized using a modified popal aqueous solution as a surface sizing agent, dried, and calendered. The treatment was carried out at a binder temperature of 3°C and a linear pressure of 70°C to a final moisture content of 8.5%. Table 2 shows the test results of the obtained paper. Table 1 2

埶、Power renderer Temperature surface

H' ¾¾? iQ| I . J \ .

τ

A A

vJ

Example 6 IJ Li Au, ff71604.0n82003.5

// 9 2 7 0 3 . 5

1 〇.3 0 0 4. 〇 Examples 6 to Ί0 and Comparative Examples 3 and 4 shown in Table 1-2 are different from Examples 1 to 5 and Comparative Examples 1 and 2 shown in Table 1. The difference is that the surface size treatment is applied to the surface of the mature calendar, while the latter is subjected to surface sizing treatment on the mature calendar, but the results are almost the same. is obtained. Examples 1-1 to 14 and Comparative Examples 5 to 6.

In Examples 1 to 5 and Comparative Examples 1 to 2 and m-like pulp and chemical blends, the absolute dry moisture content before ripening render was 1.5, 1.8, 2, 2.5, 5, respectively. Each paper was ripe calendered at a linear pressure of 150 sf/CUI temperature of 270°C. The test results of the obtained paper are shown in Table 1-3 together with the results of Example 4, TIN τ. Each paper had an internal bond strength of 2.3 cm and an air permeability of 60 sec. - 3

Absolutely dry moisture surface before ripening calender Comparative example 5 1.5 % 4.2 5 Implementation test 1 1 - 1.8 4.0

1 2 2 4 . 0

〃 1 3 2 . 5 3 . 2 5

〃 4 5 3 . 5

1 4 7 4 . 0 comparison 6 9 4 . 7 5

From Table 1-3, when the absolute dry moisture content before thermal calendaring is 8-7%, especially 2.5-5%, a smooth paper with little unevenness on the surface can be obtained. '

Examples 15-18 and Comparative Examples 7-8

With the same pulp and chemical formulations as in Examples S-Ί0 and Comparative Examples 3-4, the absolute dry moisture content before heat calendaring was 1.5, 1.8, 2, 2.5, respectively. After 5, 7 and 9% of the paper was hot calendered at a linear pressure of 150 and a temperature of 27°C prior to surface sizing, Examples 6~^! 0 and Comparative Examples 3 and 4 were treated in a similar manner to a final moisture content of 8.5%. The test results of the obtained paper are shown in Table 4 together with the results of Example 9. The air permeability of the paper before ripening calendering at this time was 60 sec, and the internal bonding strength was 2.3. Four

The unexpected examples and comparative examples shown in Table 1-4 differ from the examples and comparative examples shown in Table 1-3 in the order of surface sizing and ripe calendering. Although it is something to be done, Hoposhu-like results were obtained. '

Examples 19-21 and Comparative Example 9

With the same pulp and chemical formulation as in Examples Ί-5 and Comparative Examples ^-2, the absolute dry moisture content before heat calendaring was 5%, the air permeability was 60 sec, and the internal bond strength was 2.3½. The paper was ripe calendered at a temperature of 270 °C and linear pressures of 10, 40, 60 and 80 ½Ζ, respectively. Table 1 shows the test results of the obtained paper. table — 5

From Table 1-5, good results can be obtained when the ripening calender linear pressure is 40/ or more, especially 60// or more.

Examples 22-24 and Comparative Example 10

Example 6 ~ ^! 0 and Comparative Examples 3 to 4 and the pulp of circular shape, with a chemical blend, the absolute dry moisture content before heat calendering was 5%, the air permeability was 60 sec, and the internal bond strength was 2.3½. Prior to surface sizing, the paper was hot calendered at a temperature of 270°C and a linear pressure of 104°C, 60°C and 80°CTi, respectively. Afterwards, Examples 6 to 10 and Comparative Examples 3 to 4 were treated in a similar manner to a final moisture content of 8.5%. Table 16 shows the test results of the obtained paper.

-- 6

埶、、、 Force renderer One-line pressure surface

Comparative Example 1 〇10/cm5.0

Example 2 2 4 0 4 . 0

" 2 3 6 0 3 . 7 5

" 2 4 8 0 3 . 7 5 The examples in Table 1-6 and the specific alloys differ from the examples in Table 1-5 in the order of the surface sizing treatment and the calendering treatment, but the results are the same. was gotten .

Example 2 5

5 A pulp blended with 20 parts by weight of NBSP, 50 parts by weight of LBSP and 30 parts by weight of LBKP was beaten to a water degree of 300 g, and a sizing agent was added to the pulp slurry. as Alkylketene

- Acobel (Dick Hercue) with dimer as the main ingredient

(manufactured by Les Co., Ltd.), the main component of which is polyacrylamide as a strength agent.

Stargum (manufactured by Seiko Kagaku Co., Ltd.) with a weight of 10 and Epinox (Dick Hakukyu 0/0 by weight, ^0/0 by weight ^by ₂ , and 0.5% by weight of the pulp, _respectively , as the content in the paper sheet. to form a sheet of paper with a basis weight of 1803, dried

15 Absolute dry moisture content 2.5%, air permeability 350 sec, internal bond strength 2.3 ½f obtained by drying — CTi paper was subjected to linear pressure before surface sizing. After calendering at Ί50/ and a temperature of 270 °C, surface sizing was performed using a modified popal aqueous solution as a surface sizing agent, followed by drying. After that, it was calendered for 20 minutes at a temperature of 30°G and a linear pressure of 70 cm to a final moisture content of 8.5%. The test results of the obtained paper are shown in Table 17 together with the results of the paper of Example 9, which was obtained in the same manner as in Examples 25 except that the air permeability was set to 60 sec. show . Table 1 7

Example 26 and Comparative Example Ί1

Then, 00 parts by weight of BKP pulp was beaten to a water resistance of 300, and an alcohol containing an alkyl ketene dimer as a main component was added to the pulp slurry as a sizing agent. Pel (manufactured by Dick Hercules), stargum (manufactured by Seiko Kagaku) whose main component is polyacrylamide as a strength agent, and poly The main component is Midwepic Ruhyde U, and the amount of Epinox (made by Dick Hacuresne) is the same as the content in the paper sheet. 0.5% by weight, 2% by weight, and 0.5% by weight of the pulp, and the absolute values obtained by forming a paper sheet with a basis weight of Ί 802 and drying it. Paper with a dry moisture content of 2.5%, an air permeability of 45 sec, and an internal bond strength of 2.0 — was subjected to linear pressure of 150 ¾/ and temperature before surface sizing. After force-rendering at 20°C to 270°C, the surface was sized using a modified popal aqueous solution as a surface sizing agent, and then dried. After that, it was processed at a calendering temperature of 30°C and a linear pressure of 70°C to produce a paper with a final moisture content of 8.5%.

Furthermore, on the back side of these papers, after corona discharge treatment in advance, high-density polyethylene (density 0.968, Meldex 7) and low Density polyethylene (density 0.98 A mixture (mixture ratio) of Melt Indices 5) was coated to a thickness of 30 using an extrusion melt coater.

Next, the surface on the opposite side was subjected to the same corona discharge treatment in advance, and then a low-density polyethylene containing 9% anatase-type titanium oxide (polyethylene before pigment addition) was applied. Chetylene is coated with a density of 0.98 melt index 5) to a thickness of 25 to produce a photographic support, and further the surface of the photographic support. Then, after n-rona discharge treatment, a blue-sensitive silver bromide gelatin emulsion layer containing a yellow coupler, an intermediate layer, and a magenta color are sequentially formed adjacent to the support. an edge-sensitive silver chlorobromide gelatin emulsion layer containing an ultraviolet absorbent, an ultraviolet absorbing layer containing an ultraviolet absorber, and a red-sensitive silver chlorobromide gelatin emulsion layer containing a cyan blur and its protective layer. was applied by the extrusion method and dried to produce a multi-layered silver halide color photographic printing paper. The coating speed was 200 m/min, and the thickness of the emulsion layer after drying was measured to be Ί0 when fc.

Table 8 shows the test results. Table 1 8

Ripe calendar temperature E deviation ( ² ) Comparative example 1 1 1 2 0 Ό

Example 2 6 2 7 0 〇 Note (2):

E misalignment refers to the misalignment of some layers in the multi-layer groove formation that occurs when photographic emulsion is coated on a photographic support. It is attached and evaluated. The grade is 〇 @ 厶 ^ X, with 〇 being the best with no discrepancy, and going to X, discrepancies appear and it gets worse.

Implementation Dec 27〜 28

Pulp mixed with 20 parts by weight of NBSP, 50 parts by weight of LBSP and 30 parts by weight of LBKP was beaten to a water repellency of 300, and the resulting pulp was added to slurry as a sizing agent. Acopel (manufactured by Dick Harki-Less Co., Ltd.), the main component of which is dimer; -Gum (manufactured by Seiko Kagaku) and Epinox (manufactured by Dick Harcures), which is mainly composed of polyamide , 0.5% by weight, ^0/0 by weight of 2 and _0/0 by weight _{of 0.5} ^based on the pulp as the content in the paper sheet, respectively. A sheet of paper of Ί803 was formed and dried, and the surface size was measured using paper with an absolute dry moisture content of 2.5%, an air permeability of 45 sec, and an internal bond strength of 2.0. After calendering at a linear pressure of 150/270 and a temperature of 270, surface sizing was performed using a modified popal aqueous solution as a surface sizing agent, followed by drying. After that, it was processed at a calender temperature of 30 and a linear pressure of 70/^ to produce papers with a final moisture content of 5% and 8% (the moisture content was determined by the dryer steam). changed). 1 δ Furthermore, the back side of these papers was subjected to a corona discharge treatment in advance, and then coated with high-density polyethylene (density 0.968, melt index 7) and low-density polyethylene (density

A mixture of 0.918 and Melt Index 5) (mixture ratio) was coated to a thickness of 30 ίζ using an extrusion melt coater.

Next, the surface on the opposite side was previously subjected to a corona discharge treatment, and then a low-density polyethylene containing 9% anatase-type polyhedra Polyethylene had a density of 0.918 and was coated with a melt index 5) to a thickness of 25 Ad to produce a photographic support. A blue-sensitive silver chlorobromide gelatine emulsion layer containing a yellow fogger and an intermediate layer are applied to the surface of this photographic support, after corona discharge treatment, adjacent to the support. , a green-sensitive silver chlorobromide gelatin emulsion layer containing a magenta blur, an ultraviolet absorbing layer containing an ultraviolet absorber, and a red-sensitive silver chlorobromide gelatin emulsion containing a cyan blur. A multilayer silver halide color photographic printing paper was prepared by coating the layer and its protective layer by the extrusion method and drying.

After each sample obtained as described above was subjected to heat treatment, color photographic paper cut to a certain ώ size was weighed, placed in a color processor, and colored. Develop for 2 minutes and 30 seconds, desilver and fix for 3 minutes, wash with water for 1 minute, pull out the still wet photographic paper, and wipe off water droplets on both sides with a cloth. The weight was quickly measured so as not to dry, and the amount of liquid absorbed into the emulsion was measured. The results are shown in Table 1-9. ' Table 1 9

Note (3)

The liquid absorption amount is calculated by the following formula.

Amount of liquid absorbed (3. No) - Print weight after processing (No)

1. Weight of photographic paper before processing (3 / τιΠ liquid absorption: 1). occur.

Example 2 9

Pulp mixed with 20 parts by weight of ΝΒS, 50 parts by weight of BSP, and 30 parts by weight of BKP was beaten to a freshness of 300, and a sizing agent was added to the pulp slurry. Acopel (manufactured by Dyzku Hercules), which has alkylketene dimer as its main component, and polyacrylamide as its main component, is used as a strength agent. Stargum (manufactured by Seiko Kagaku) and Epinox (manufactured by Deitz Hercules), whose main component is polyamide epichlorohydrin was added to the pulp in amounts of 0.5% by weight, 2% by weight, and 0.5% by weight, respectively, as the amount contained in the paper sheet. A sheet of paper of Ί803 was formed and dried, and the paper with absolute dry moisture content of 2.5%, air permeability of 60 sec, and internal bond strength of 2.3 K was subjected to surface sizing. After calendering at a linear pressure of Ί 50 KS / m and a temperature of 270 After surface sizing using modified popal water solution as surface sizing agent and drying, the final thickness is Ί65 at calendar temperature 30 °G. Similarly, the linear pressure was adjusted to Ί5〇^ to give a final moisture content of 8.5%. The test results of the obtained paper are shown in Table 10. Table Ί0 shows the results obtained under the same conditions as in Example 29 except that the final calendering pressure was adjusted to 70 Z CTi in order to obtain a final thickness of Ί75. The test results for the paper in Experiment 9 are also shown. Table — 1 0

Note (4):

Taber stiffness is a measure of the stiffness of paper measured by a Taber tester (see JIS-P-825 for details).

Example 3 0 and Comparative Example 1 2

L ΒΚ Ρ 100 parts by weight of NOLP was beaten to a water repellency of 300^, and the resulting pulp slurry was mixed with alkyl ketene dimer as a sizing agent. Accobel (manufactured by Dick Hachicules) to Epinox (dichloromethane), the main component of which is polyamidepichlorohydrin (manufactured by Co., Ltd.) was added to 0.5% by weight, 2% by weight, and 0.5% by weight of the pulp, respectively. Paper with absolute dry moisture content of 2.5%, air permeability of 45 seconds and internal bond strength of 2.0½-0?1 obtained by forming a paper sheet with a tsubo of 80S and drying it. Before surface sizing, the pressure was set to Ί50an, the temperature to Ί20, and the temperature to 270, respectively. It was subjected to surface size treatment using a modified poval aqueous solution as a base , dried , then treated at a calendar temperature of 30 and an atmospheric pressure of Ί503/an to a final moisture content of 8 . 5% of paper produced. In addition, after corona discharge treatment on both sides of these papers in advance, high-density polyethylene (density 0.968, melt index 7) and low-density polyethylene (density: 0.918, melt index: 5) (mixture ratio - 1Z1) extruded. Coated to thickness.

Next, the surface on the opposite side was subjected to a corona discharge treatment in advance, and then a low-density polyethylene containing 9% anatase-type titanium oxide (before pigment addition) was applied. Polyethylene was coated with a density of 0.918 melt index 5) to a thickness of 25/ to produce a photographic support. The test results of the obtained photographic support are shown in Table 1-2. Table 1 1 2

Implementation 3 1

Manufactured with the same formulation as in Example 28, the final calendering pressure was adjusted to 70/ so that the thickness of the paper was Ί75ζ, and both sides were coated with a circumferential coating. Table 1-13 shows the result of producing a photographic support by using this method. Table 1 13

Ripe calendar Final calendar Job 4 Thickness Taber stiffness Surface texture Temperature Pressure

Example 31 270°C 7QKs/cm 175 17.5 -c 4.0

Claims

Amended Claims [Accepted by the International Bureau on July 7, 1986 (07.07.86); claim 1 as originally filed is amended; other claims are unchanged (page 2)]

(1) (After correction) Paper with an absolute dry h content of 1.8 to 7% was removed from a metal roll under the conditions of a temperature of 150 to 3000 and a linear pressure of 40% or more. A method for producing paper, characterized in that the paper is ripened calendered in a ripened calendering device.

(2) The method of claim Ί, wherein the ripening calendering temperature is between 160°C and 2°C.

(3) The linear pressure of heat calendering is 60C or more.

10. The method of claim 1.

(4) Bone dry moisture of hot calendered paper is 2.5

~5%.

(5) The method according to claim Ί, wherein the paper to be thermally calendered has an air permeability of 300 sec or less.

15

(6) The method of claim Ί, wherein after ripening calendering, moisture is added to adjust the final moisture content.

(7) Aqueous solutions in which water contains one or more additives selected from surface strength agents, dyes, fluorescent agents, antistatic agents, anticaptive agents, or their peripheral effects. granted using

20. The method of claim 6.

(8) Claims 6 or 7, wherein the final moisture content is adjusted by applying an aqueous solution treatment after ripe calendering, followed by a subsequent power-rendering treatment. Described method.

(9) Claim 6 that adjusts the final moisture content to 6% or more

The method according to any one of items 25 to 8, Ί. (10) A method according to any one of claims 6 to 9, wherein the resulting mature-rendered paper is a photographic paper support.

11. The method of claim 10 wherein the 165 thick photographic paper support has a taper of 11 or greater.

(12) The method of claim 10, wherein the 175-thick photographic paper support has a taper angle of 131 or more.

(13) The method described in item 10 of the scope of the above, wherein a resin coating layer is provided on one or both sides of the photographic paper support.

(14) A resin-coated photographic paper support having a thickness of 220 U and having a resin coating layer provided on both sides of a photographic paper support having a thickness of Ί6.59. The method of claim Ί3 having a Taber angle of JL hereinafter.

(15) A resin-coated photographic paper support having a thickness of 230^ and having resin coating layers provided on both sides of a photographic paper support having a thickness of 175 cm and a thickness of Ί9 Sf-cm or more. A claim having a cutting degree Method according to claim 13

Sentences under Article 19:

In the amendment based on Article 19 of the Patent Cooperation Treaty, which was made this time, the heat calendering treatment in paragraph 1 of the scope of claim was carried out by a hot calendering device consisting of metal rolls. I'm going to clarify what I'm doing. i A ripe calender device consisting of metal rolls” was clarified at the time of filing! Although it is not specified, there is a description on page 3, lines 4-5 of the specification that ``heating is performed by using means such as electromagnetic induction.'' The elastic rolls used as the rollers cannot be heated by electromagnetic induction, and the ones that can be heated by magnetic induction are limited to metal rolls. The applicant believes that the introduction of the above language into claim 1 is an amendment to the scope of the disclosure in the original specification, as it would be obvious to a person skilled in the art.

In JP, B 1, 38-1009 (Japanese Patent Publication No. 38-10Q9) cited in the international search report, an elastic roll such as a spa-strength renderer is used. However, it is difficult to apply high pressure with elastic rolls. On the other hand, in the metal rolls (i.e., calender rolls, etc.) used in the present invention, the contact area of the nips is extremely small, so high pressure can be efficiently applied. You can target it.

• These days, the absolute dry moisture content is within a predetermined range (1.8 to 7%). 2 et al

The method for producing thermally calendered paper is the method for producing thermally calendered paper by subjecting the paper to thermal calendering under prescribed conditions. does not disclose or imply For example, with respect to water content, the cited documents only disclose 0 to 50%, preferably about 35% or less, as water content, and examples show that There is no disclosure of any numerical limit of 1.8% to 7% absolute dry moisture content of the present invention, which is well-supported of critical significance.